The White House moved Friday to make nearly all federally funded research freely available to the public, the latest advance in a long-running battle over access to research that exploded into view last month after the suicide of free-information activist Aaron Swartz.

In a memo, White House science adviser John P. Holdren directed agency leaders to develop rules for releasing federally backed research within a year of publication in scientific or technical journals.

The directive affects agencies funding at least $100 million in research annually, including the National Science Foundation and the Departments of Defense, Agriculture, Commerce, and Health and Human Services. Agencies have six months to develop plans, which will then be reviewed by the White House before launch.

Articles can be stored in agency computers or other digital repositories as long as they can be "publicly accessible to search, retrieve, and analyze," Holdren wrote. He encouraged agencies to coordinate their plans.

Currently, much taxpayer-funded research is published in academic journals that cost up to $20,000 a year. Reading individual articles typically runs $30 or more.

Holdren on Friday also responded to an open-access petition that garnered 65,000 signatures, writing, "this research was funded by taxpayer dollars. Americans should have easy access to the results."

A teenage scientist from Glen Burnie, Jack Andraka, said he relied on open-access articles to develop a five-minute, $3 test for pancreatic cancer. The project earned him first place and $75,000 in last year's Intel International Science and Engineering Fair.

"I kept running into these paywalls where articles cost $30," said Andraka. He then searched for similar, but freely available, information. "Open access was absolutely critical. I couldn't have done my project without it."

The new policy traverses a middle ground between the demands of advocates for immediate free access to research and the pecuniary interests of the $21 billion academic publishing sector. It appeared to placate large segments of both sides.

The Association of American Publishers, which has fought open-access proposals in Congress, called the policy a "fair path." A coalition of academic libraries fed up with high journal prices also praised the plan.

"I think it's a huge step in the right direction," said Heather Joseph, executive director of the Scholarly Publishing and Academic Resources Coalition, which represents libraries.

Some open-access advocates, meanwhile, took issue with the policy's one-year waiting period.

"It's lame," said Michael Eisen, a University of California, Berkeley, biologist and a vocal proponent of immediate free access to research papers. "It's a major sellout to publishers."

Holdren's memo explicitly recognizes "that publishers provide valuable services," such as coordinating the review of submitted articles by scientific peers. So-called peer review is a cornerstone of the scientific process. "It is critical that these services continue to be made available," Holdren wrote.

For three years, Congress has wrestled with the issue but has passed no legislation. A bipartisan bill introduced last week, the Fair Access to Science and Technology Research Act, would force the public release of journal articles within six months of publication. The publishing industry vehemently opposes the bill. In 2011, a bill backed by academic publishing powerhouse Elsevier aimed to quash open access to scientific articles; it died after an organized outcry.

Already, the nation's largest funder of research, the National Institutes of Health, makes available papers arising from research it funds within a year of publication. A 2007 law mandated that move. Some 40 percent of the users of the NIH database PubMed are non-academics, according to an NIH report.

The huge and growing availability of full-text medical and biology papers isn't just a consequence of the NIH law, however. Most of the papers are ones that journals have voluntarily offered to provide without charge and often include studies published many years ago.

"What the White House announced is already happening in biomedicine," said Donald Lindberg, the physician who heads the National Library of Medicine, the branch of NIH that operates PubMed.

Lindberg added, however, that an increasing amount of research is being paid for by pharmaceutical and biotech companies, which are not subject to the open access rules. Less than 20 percent of the clinical trials of new drugs and devices are paid for by the federal government.

In other federal agencies sponsoring research, the new directive is likely to make more of a difference.

The National Science Foundation is the chief government sponsor of non-medical scientific research. Its funding produces 25,000 to 40,000 publications a year from thousands of academic researchers, said Myron Gutmann, NSF's assistant director.

Unlike medical research, the NSF-funded studies aren't catalogued in a common database like PubMed. Instead, the wide variety of fields — physics, chemistry, mathematics, engineering, social sciences — have their own electronic archives. One of the goals of the policy announced Friday is to make searching those archives easier and quicker.

"What is exciting is to expose across many domains of science as much knowledge as possible so that innovation can take place," Gutmann said.

Scientists at the U.S. Department of Agriculture produce about 10,000 research papers a year, with several thousand more written by outside scientists funded by USDA. The department believes that open access to agricultural research could cut in half the time required to produce plant varieties with desirable traits, such as resistance to drought or pests. This access will be especially useful to plant breeders in developing countries, said Catherine E. Woteki, USDA's chief scientist.

"We think this is a big deal," she said.

Selling archived copies of articles is a big business for journal publishers. One of the largest is Springer, a Germany-based company that publishes about 2,500 journals, with about 330 of them open-access.

"Springer seeks to ensure broad access to its content — this is the goal of all publishers," said Eric Merkel-Sobotta, a Springer spokesman. He said that the White House policy "appears to support the idea that embargo periods of different length may be necessary, depending on discipline." An article on a medical topic might be obsolete six months after publication, while one on an issue in mathematics "might still be highly relevant after five years."

The open-access movement launched about a decade ago as the high cost of academic journals spurred libraries, scientists, and activists to search for ways to upend the 200-year-old stranglehold on scientific information enjoyed by academic publishers.

In 2003, a vanguard of scientists launched the Public Library of Science, now a series of free journals that attract submissions from top-name scientists. PLoS, as the journals are known, flips on its head the standard business model in which journals charge their readers. Instead, researchers pay to publish there and anyone can read the results. Another open-access biology journal, eLife, launched last year and relies on grants to operate.

"Open access" has also become a rallying cry for activists trying to set information free. Swartz, 26, a prominent computer programmer, faced severe federal charges for allegedly downloading some 5 million academic articles from JSTOR, a pay-walled journal repository. Swartz died by suicide in January as a court date loomed.

The hacker group Anonymous then broke into MIT's computer network and promised to continue Swartz's crusade.

"The world's entire scientific and cultural heritage, published over centuries in books and journals, is increasingly being digitized and locked up by a handful of private corporations," the group wrote. "We need to buy secret databases and put them on the Web. We need to download scientific journals and upload them to file sharing networks. We need to fight for Guerilla Open Access."